U.S. Pat. No. 3,748,884, granted to Dan L. Colbath on July 31, 1973, discloses a roll-forming machine including a plurality of roll-stands each comprising cooperating non-forming rollers which function to move material along a predetermined path. The roll-forming machine further includes a plurality of die-stands each comprising non-driven material engaging rollers which function to transform the material from an initial configuration to a desired configuration. The die-stands are mounted on and positioned relative to the path by an elongate, rigid spine. This permits conversion of the machine from one roll-forming configuration to another by removing the spine and the die-stands attached thereto and then installing a different spine/die-stand assembly in the roll-forming machine.
In co-pending application Ser. No. 355,673 there is disclosed a roll-forming machine also including roll-stands for transporting material along a predetermined path and die-stands for progressively transforming the material from an initial configuration to a desired configuration. The roll-forming machine is similar to that described above in connection with U.S. Pat. No. 3,748,884 in that the die-stands are mounted on a rigid spine to facilitate conversion of the roll-forming machine from one roll-forming configuration to another. A major difference between the two roll-forming machines relates to the fact that in the latter machine the roll-stands comprise nonforming lower driving rollers only. Idler rollers are mounted on the spine for cooperation with the lower driving rollers to drive material through the roll-forming machine.
Although roll-forming machines incorporating the abovedescribed invention have enjoyed substantial commercial success, certain problems have been encountered in their use. For example, in both machines the positioning of the material driving rollers of the roll-stands transversely relative to the direction of material movement is fixed. This is somewhat limiting with respect to the width of materials that can be accommodated in the roll-forming machine. Another problem relates to the fact that in both of the prior roll-forming machines employ a common drive system for all of the roll-stands. This has been found to be somewhat cumbersome with respect to subsequent changes in the number and/or the positioning of the roll-stands.
The present invention comprises improvements in roll-stands for roll-forming machines which overcome these and other problems of the prior art. In accordance with the broader aspects of the invention, a roll-stand comprises at least one lower roller which is selectively positionable transversely with respect to the path of material movement through the roll-forming machine. By this means materials of various widths are accommodated in the roll-forming machine. The roll-stands may be actuated either by means of a common drive system or by means of individual drive motors each drivingly connected to the roller in one of the roll-stands.
In accordance with more specific aspects of the invention, each roll-stand may further include a pair of upper rollers which are floatingly supported so as to accommodate materials of various thicknesses in the roll-forming machine. In such instances the upper rollers are also selectively positionable transversely relative to the path of material movement and are driven either by the common power source or by an individual drive motor. Alternatively, there may be provided idler rollers mounted on the spine for cooperation with the lower rollers to move material through the roll-forming machine.
The material driving rollers of the roll-stands may be arranged in pairs, and each roller rotatably supported by a bearing block. The bearing blocks are selectively positionable transversely with respect to the direction of material movement. A drive shaft extends through each pair of rollers and structure is provided for constraining the rollers to rotation with the drive shaft. The drive shaft is in turn drivingly connected either to a drive system common to all of the roll-stands or to a drive motor individual to the associated pair of rollers.